Reciprocating engines, often called piston engines, are well known and extensively used throughout the world. The main types of reciprocating engines are the internal combustion engine, the steam engine and the Stirling engine. In all three types, one or more cylinders with a reciprocating piston inside produces a linear motion which is transferred to a crankshaft to produce a rotary motion. The rotary motion is then used for a work task by way of various gears, etc. The most prevalent of the engines is a four stroke cycle internal combustion engine used to power motor vehicles.
While well known and commonly accepted, the common internal combustion engine needs to be improved upon to conserve dwindling energy sources and reduce emissions. Current designs are less than 20% efficient with over 60% of losses in wasted heat energy.
A reciprocating engine is needed which is more efficient in operation than the common internal combustion engines. A source of power to move pistons within cylinders of such engines which does not use internal combustion is needed. Still further, the ability to use a non-petroleum fuel such as a refrigerant and natural gas to power the engine is needed.
A non-internal combustion reciprocating engine as the sole source of powering a motor vehicle would be ideal, though given the power and speed demands of such vehicles may be difficult to achieve. Still, an auxiliary engine in the vehicle which can at the least drive a generator to meet the electrical power requirements of the vehicle would be a meaningful and beneficial advance.